<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        input[type='text']::-webkit-input-placeholder{
            color: red;
        }
        input[type='text']{
            border: 1px solid pink;
        }
        input[type='checkbox']{
            width: 100px;
            height: 100px;
        }
    </style>
</head>
<body>
    <form action="http://baidu.com" method="GET" autocomplete="off">
        <input type="text" placeholder="我是某某某" autofocus="autofocus"><br>
        <input type="text"><br>
        <input type="checkbox"><br>
        <input type="submit" value="提交">
    </form>
</body>
</html>